We evaluated the characteristics of traumatic injury and risk for subsequent trauma in infants less than three months of age (n = 111). Medical records were reviewed at presentation and one year later. Injury was due to abuse/neglect in 28%, whereas 72% were accidentally injured. Falls were the most common mechanism of accidental injury (67%). The percentage of infants with skull fractures was greater in the abuse/neglect group than in the accidental group (7/31 vs 7/80; P < 0.05) with a tendancy toward more diastatic and multiple skull fractures (6/7 vs 2/7) as well as intracranial hemorrhages (3/7 vs 0/7). More infants in the abuse/neglect group suffered extremity fractures (4/31 vs 2/80; P < 0.05). Hospitalization was more frequent (12/31 vs 8/80; P < 0.001), as was social or protective service intervention (25/31 vs 17/80; P < 0.001), in the abuse/neglect group. The two groups showed no difference in the number of previous emergency department (ED) visits; however, the use of the ED declined significantly in the abuse/neglect group following the trauma (0.81 +/- 1.2 vs 1.5 +/- 2.1 visits; P < 0.05). The abuse/neglect group tended to have a greater number of subsequent traumatic injuries than those accidentally injured. Abuse/neglect should be considered in any seriously injured infant less than three months of age because of the likelihood of subsequent trauma.